Electrical apparatus



April 30, 1963 B. coLTEN 3,088,087

ELECTRICAL APPARATUS Filed June 27, 1960 .2 sheets-sheet 1 F/ I /eeee eee@ @eee /2 can@ @eee @een INVENTOR. BERNARD 001. rE/v ATTORNEY April 30, 1963 B. COLTEN ELECTRICAL APPARATUS Filed June 27, 1960 2 Sheets-Sheet 2 4g 4b '52 *v50 JNVENToR. BERNARD cous/v ATTORNEY United States Patent tice 3,088,087 Patented Apr. 30, 1963 3,088,087 ELECTRICAL APPARATUS Bernard Colten, Waltham, Mass., assigner to Minneapoiis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Filed June 27, 1960, Ser. No. 39,113 3 Claims. (Cl. 339-13) The present invention relates in general to a new and improved apparatus for testing the individual connections of a connector assembly, and in particular to test apparatus which is specifically adapted to lcooperate with a connector assembly of the type having a planar array of connector pins.

I-Ieretofore, when testing connector assemblies of this type, test connections to the individual connector pins were ygenerally made by means of alligator clips which were directly clipped onto the pins. If more than one connection was required, .additional alligator clips were fastened either to the first 'clip or -to the connector pin if there was room on it.

Despite the temporary nature of the test connection, such .an arrangement is unsatisfactory, at best. Not only does it increase the chance of short circuits in view of the relatively close spacing of the pins in the array, but it also has `a tendency of obstructing access to the pins and obscuring them to an extent where an orderly test procedure becomes dilicult to carry out. Where the connector assembly has connector pins of the type which are individually adapted for wire-wrapped connections, the danger of damaging the wire-wrapped connections must also be taken into account, particularly where more than one clip is fastened onto a connector pin. This is particularly true where only a short section of the pin is free of wirewrapped connections and the temptation eXists of attaching the alligator clip directly to these connections. Furthermore, since -a pulling force may be applied to a single pin by several alligator clips and their connected conducto-rs, the possibility of damage to the pin cannot be discounted. Even if the applied force fails to snap the pin, excessive bending may result which may cause a short circuit between the connections on adjacently disposed pins.

Accordingly, it is the primary object of this invention to provide test equipment for use with a connector assembly of the type having a planar array of connector pins wherein the foregoing disadvantages are overcome.

I-t is another object of this invention to provide test equipment of the type referred to above, whe-rein complete isolation is maintained between the connector pins while probing.

It is a further object of this invention to provide test equipment of the ytype referred to above wherein test probes are supported independently of the connector pins and a negligible load is applied to the latter regardless of the number of connections made thereto.

It is an additional object of this invention to provide test equipment of the type referred to above wherein the connector pins may be readily ideutiied and connections thereto are easily effected to permit a rapid testing operation.

In brief, the present invention comprises a test panel wherein a plurality of holes are arranged to correspond respectively to the connector pins of a connector assembly. Each hole includes 'a provision for insertion of a test probe, one end of lwhich is adapted to make electrical cont-act with its corresponding connector pin when the test panel is mounted in its operating position. By means of a conductive connect-ion on each test nprobe, any desired component may be connected thereto, thereby electrically linking said component to the corresponding coni nector pin.

The various novel features which characterize the invention 'are pointed out with panticularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its advantages and specific objects thereof, reference should be had to the following detailed description and the accompanying `drawings in which:

FGURE l illustrates one embodiment of a test panel;

FIGURE 2 illustrates the same test panel mounted in operating position with respect to a connector assembly;

FlGURE 3 illustrates the connection between one embodiment of a test probe and a connector pin; and

FIGURE 4 illustrates two test probes conductively connected to a single connector pin'.

With reference now to the drawings, FIGURE 1 shows one embodiment of a test panel 8 which consists of a nonconductive material. A positioning hole 10 is located at each corner of the panel and traverses the latterV between its front surface 12 `and its rear surface 14. The probe holes y16 also traverse the thickness of fthe test panel and are arranged in a predetermined pattern corresponding to the connector pin array of the connector assembly with which the test panel i-s to be used.

FIGURE 2 illustrates one embodiment for mounting fthe test panel 8 in its operating position. The front surface 12 is seen to be spaced from the connector .assembly 1S. Although the assembly may have any desired number of connector pins 28, only siX pins are illustrated in FIGURE 2 for the sake of clarity. The connector pins extend outwardly from a pair of supports 22 and are arranged in a parallel array with their terminal portions 38 disposed in a common plane. Each connector pin has a square or a rectangular cross-section in order to facilitate the making of wire-wrapped connections. It will be understood that each wire which is used in a wire-wrapped connection, although shown in portion only in the drawing, is further connected to any desired point. For example, two wire-wrapped connections may be connected together so as to provide a permanent connection between the two corresponding connector pins. Each pin may carry more than one wire-wrapped connection, as is illustrated in connection with the pin 28 which carries the connections 26 and 30.

In .the embodiment of FIGURE 2, the spacing of the test panel 8 from the connector assembly 18 is determined by the hollow spacers 32, which are respectively disposed in each corner between the front surface 12 of the test panel and .the connector assembly 18. A shaft 34 which has a threaded end, extends through the hollow spacer 32 and through the hole 10 -in the test panel whence it :appears at the rear surface 14 thereof. A Wingnut 35 mates with the threaded shaft end and is adapted to tighten each corner of the test panel against the spacer 32 to hold the panel in its operating position. In this position, the holes 16 and their corresponding connector pins 28 are aligned with each other, the spacing between the test lpanel and the connector assembly being chosen so that the unwrapped terminal portion 38 of each connector pin 28 extends a predetermined distance into its corresponding test panel hole.

In FIGURE 2 `a test probe 40 is seen to |be iin-sented in one of the holes 16. The externalV shoulder 42 of the probe abuts the rear surface 14 and determines the extent of probe insertion into the test panel hole. The test panel spacing from Athe connector assembly and the extent ost probe insertion lare chosen to provide 'a mating arrangement of the probe with the unwrapped terminal portion 38 Iof the pin 2S. The test probe 42 consists of Ia conductive material :and has a conductor 44 connected thereto.

aoeaosv These features are shown in greater detail in FIGURE 3, applicable reference numerals having ybeen retained. In practice, the probe 40 contacts the initial wall por-tions 46 of the hole 16 -to provide a tit in the region 46 suliciently tight to lend support to the probe and :to prevent it from being involuntarily dislodged. The test probe 40 terminates in a concave end 48 which mates with the terminal portion 3S of the connector pin 2S to provide an electrical connection between the pin and the probe. The shoulder 42 has an opening 50 which exposes a hollow interior with tapered walls l52. The conductor 44, which is connected to the shoulder 42 of the test probe, is used to establish a connection with whatever test instrument is used to measure the signal existing on the connector pin 28, Ior -to effect an electrical connection of the latter to an externally located component.

FIGURE 4 illustrates the use of two test probes in superposed relationship to establish a dual connection to the connector pin 28. While the test probe 40 is supported in the hole 16 by frictional engagement with the walls of the latter in the region 46, the additional test probe 40' is supported solely by the loriginal test probe 40. This latter support is entirely due to the frictional engagement in the region 54 between the exterior walls of 4the test probe 40' and the interior -tapered walls 52 of the test probe 40. With this arrangement, the signals on the connector pin 28 are available on conductor 44, as well as on conductor 44. Further test probes may be added and supported in the same manner in order to increase the number of connections to the connector pin 28.

From the foregoing explanation and from the drawings it will be apparent that the `apparatus which comprises the subject matter of this invention enables the person making the test to make any desired number off connecions to a single -connector pin without applying an undue mechanical load to the latter. Such connections `are carried out in complete isolation from the remaining connector pins so that the danger of short circuits during testing is eliminated. If desired, certain surfaces of the respective test probes may be marked or color-coded to provide a ready identification of the connector pins to which the test probes are connected. Similarly, the test panel itself may be color-coded or it may carry pertinent designations to indicate the particular signals available at each hole, or at each group of holes. The latter oase is illustrated in FIGURE l by the hole groupings A, B and C. Since the test panel may be easily dismounted and interchanged by removing the wingnuts 36, the invention lends itself readily to `dilierent test conditions. A complete `array of test panels could replace one surface of the conventional external sheet metal cover which is used in presently available equipment. With the present invention it is possible to obtain a large number of test points by means of independently supported and mutually isolated test probes to enable the user to carry out tests and circuit changes in a rapid and efficient manner.

It will be understood that the invention is not restricted to the preferred embodiment which is illustrated in the drawings, and is applicable to connector assemblies off many different types. Thus, the mating engagement between the terminal portion of the connector pin and the test probe need not be carried out in the manner shown herein, provided only an electrical connection is established. For example, yby increasing the length of the spacers 32 the connector pins will not enter the holes 16. In this case, the test probes 40 must be sulhciently long to extend beyond the front surface 12 of the test panel in order to engage the pins 28. Such an arrangement could be ernployed where it is desired to gain additional space on each -pin in order to make further wire-wrapped connections thereon.

The connector pins are not, of course, limited -to the construction shown. For example, the hollow test probes could readily be modified to -accept electrical components other than :additional test probes. Similarly, the means for mounting test panels are not restricted to the illustrated construction and may be readily modied to suit the needs of a particular situation. For example, arrangements for mounting and dismounting the test panel more rapidly than is possible by the use of the illustrated wingnuts 36 will readily occur to those skilled in the tart.

Although the removability of the test probes 40 adds a degree of liexibility to the invention, it may be desirable under certain conditions to fix the test probes permanently in their respective holes. With the latter arrangement, all the test probes are connected to vtheir respective connector pins when the test panel is mounted in its operating position.

It will be apparent from the foregoing disclosure of a preferred embodiment of the invention that numerous modifications, changes and equivalents will now occur to those skilled in the art, all of which fall within the true spirit and scope contemplated by the invention.

What is claimed is:

1. In combination with a lixed connector assembly of the type having a plurality of connector pins disposed in a planar array on a support, each of said pins including a terminal portion and having at least one wire-wrapped electrical connection between said terminal portion and said support, a non-conductive test panel comprising front and rear surfaces, a plurality of holes in said panel disposed in corresponding relationship to the connector pins of said planar array, a plurality of conductive test probes inserted in said holes and supported therein in individually removable relationship through said rear surface, each of said probes including a shoulder abutting said rear surface to limit the extent of insertion into said test panel to a point prior to said front surface, each of said probes terminating in a concave end portion removably adapted to enage the terminal portion of a connector pin to make electrical contact therewith, a conductor connected to each of said probes, and means for mounting said test panel in a predetermined operating position with said front surface facing said assembly and spaced therefrom to provide a mating engagement of said probes with their corresponding connector pins within the holes of said test panel, said panel being removable from its mounting in a direction away from said assembly.

2. The apparatus of claim 1 wherein each of said test probes further includes a hollow tapered interior section accessible through a concentric opening in said shoulder, said interior probe section being adapted to receive the inserted end portion of an additional substantially identical test probe and to removably support the latter in electrical contact therewith.

3. The apparatus of claim l and further comprising means disposed on said test panel for identifying said connector pins.

References Cited in the le of this patent UNITED STATES PATENTS 2,424,528 Wild July 2.2, 1947 2,485,986 Reid et al. Oct. 25, 1949 2,506,615 Rosen May 9, 1950 2,510,339 Heiss June 6, 1950 2,594,069 Poehlmann Apr. 22, 1952 2,647,244 Dewey et al July 28, 1953 2,738,484 Beckman et al. Mar. 13, 1956 2,754,454 McNutt et al. July l0, 1956 2,938,068 Silverschotz May 24, 1960 FOREIGN PATENTS 617,539 Great Britain Feb. 8, 1949 414,488 Italy Aug. 7, 1946 OTHER REFERENCES IBM Technical Disclosure, vol. 2, no. 1, June 1959, pages 10 and 11. 

1. IN COMBINATION WITH A FIXED CONNECTOR ASSEMBLY OF THE TYPE HAVING A PLURALITY OF CONNECTOR PINS DISPOSED IN A PLANAR ARRAY ON A SUPPORT, EACH OF SAID PINS INCLUDING A TERMINAL PORTION AND HAVING AT LEAST ONE WIRE-WRAPPED ELECTRICAL CONNECTION BETWEEN SAID TERMINAL PORTION AND SAID SUPPORT, A NON-CONDUCTIVE TEST PANEL COMPRISING FRONT AND REAR SURFACES, A PLURALITY OF HOLES IN SAID PANEL DISPOSED IN CORRESPONDING RELATIONSHIP TO THE CONNECTOR PINS OF SAID PLANAR ARRAY, A PLURALITY OF CONDUCTIVE TEST PROBES INSERTED IN SAID HOLES AND SUPPORTED THEREIN IN INDIVIDUALLY REMOVABLE RELATIONSHIP THROUGH SAID REAR SURFACE, EACH OF SAID PROBES INCLUDING A SHOULDER ABUTTING SAID REAR SURFACE TO LIMIT THE EXTENT OF INSERTION INTO SAID TEST PANEL TO A POINT PRIOR TO SAID FRONT SURFACE, EACH OF SAID PROBES TERMINATING IN A CONCAVE END PORTION REMOVABLY ADAPTED TO ENGAGE THE TERMINAL PORTION OF A CONNECTOR PIN TO MAKE ELECTRICAL CONTACT THEREWITH, A CONDUCTOR CONNECTED TO EACH OF SAID PROBES, AND MEANS FOR MOUNTING SAID TEST PANEL IN A PREDETERMINED OPERATING POSITION WITH SAID FRONT SURFACE FACING SAID ASSEMBLY AND SPACED THEREFROM TO PROVIDE A MATING ENGAGEMENT OF SAID PROBES WITH THEIR CORRESPONDING CONNECTOR PINS WITHIN THE HOLES OF SAID TEST PANEL, SAID PANEL BEING REMOVABLE FROM ITS MOUNTING IN A DIRECTION AWAY FROM SAID ASSEMBLY. 